Liquid crystal display (LCD) has many advantages, such as thin body, power saving, no radiation, and has been widely used. Such as: LCD TVs, mobile phones, personal digital assistants (PDAs), digital cameras, computer screens or laptop screens, etc., in the field of flat panel display dominant.
Most of the liquid crystal displays on the market are backlight type liquid crystal displays, which include a liquid crystal display panel and a backlight module. The operating principle of the liquid crystal display panel is to inject liquid crystal molecules between the thin film transistor array substrate (TFT Array Substrate) and the color filter (CF) substrate and apply a driving voltage on the two substrates to control the rotation direction of the liquid crystal molecules, so as to refract the light of the backlight module to generate a picture.
Due to the optical anisotropy of liquid crystal molecules, there is a problem of color shift in a large viewing angle in a liquid crystal panel. In order to solve the color shift phenomenon under a large viewing angle of a liquid crystal panel, the prior art proposes a color shift compensation algorithm by preprocessing an input data signal. The color shift compensation algorithm specific implementation steps include: respectively acquiring the first display grayscale value and the second display grayscale value by the original grayscale values of the respective primary color components of the respective image pixels of the image to be displayed, respectively controlling the display brightness of two sub-pixels of the same color on the liquid crystal panel by using the first display grayscale value and the second display grayscale value. Wherein the first display grayscale value is greater than the second display grayscale value such that the driving voltages applied to the two sub-pixels are not the same so that the liquid crystal molecules of the two sub-pixels are deflected to different angles, so as to viewing the screen at different angles can get better viewing results, to achieve the purpose of reducing color cast. Wherein an image is usually composed of a plurality of image pixels, each image pixel includes three primary color components of red, green and blue, in driving an image display, the brightness of the primary color component is controlled by providing a grayscale value for display for each primary color component of each image pixel so that the primary color component displays a corresponding color, thereby realizing the display of the image. In one image pixel, each of the primary color components controls two sub-pixels of the same color and adjacent to each other, that is, the red component correspondingly controls two adjacent red sub-pixels, the green component correspondingly controls two adjacent green sub-pixels, the blue component correspondingly controls two adjacent blue sub-pixels, so that the display brightness of the corresponding two red sub-pixels is respectively controlled by the first display grayscale and the second display grayscale generated by the original grayscale values of the red component, the display brightness of the corresponding two green sub-pixels is respectively controlled by the first display grayscale and the second display grayscale generated by the original grayscale values of the green component, the display brightness of the corresponding two blue sub-pixels is respectively controlled by the first display grayscale and the second display grayscale generated by the original grayscale values of the blue component. The display brightness of each image pixel is a mixture of the display brightness of its corresponding primary color component, the display brightness of each primary color component is a mixture of the display brightness of its corresponding two sub-pixels. Generally, in order to keep the display brightness of the two sub-pixels controlled by the original grayscales consistent with the display brightness of the two sub-pixels controlled by the first display grayscale and the second display grayscale. It is generally set that the sum of the display brightness corresponding to the first display grayscale value and the display brightness corresponding to the second display grayscale value is equal to twice the display brightness corresponding to the original grayscale value.
In addition, in the image processing, the image where the brightness or grayscale changes intensely is called the high-frequency component, otherwise the low-frequency component. In the prior art, the detection of the high-frequency components in the image is limited to the detected image pixels and the image pixels adjacent thereto, and the detection range is small. In this case, high-frequency components after the color shift compensation algorithm will appear grainy, resulting in reduced display quality.